* Mercury

* Venus

Why?

Opposition occurs when a planet is directly opposite the Sun in the sky from our perspective on Earth. This alignment means that the planet is visible all night long and is at its brightest.

* Mercury and Venus are both inner planets, meaning they orbit closer to the Sun than Earth does.

* Because of their close proximity to the Sun, they never get far enough away from it to be in a position directly opposite the Sun from Earth's perspective.

Instead of opposition, Mercury and Venus can be seen at inferior conjunction (between the Earth and the Sun) or superior conjunction (behind the Sun).